I told a friend at work about this post. He said that his friend, a deputy for the sheriffs department, bought one a while back, to use as a back up gun. They took it to the range to fire it for the first time, and not even through the first mag, the same thing happened to him. He said the slide just came off and went downrange a few feet. He said it was a 9mm ADP.
I wasn't there to witness it, but that is the story he told me.